1. Field of the Invention
The present invention relates to a lathe, a computer program for lathe control, and a machining method by a lathe.
2. Description of the Related Art
In machining a work by a lathe, the relative position of a tool to the work must be determined as accurately as possible. In order to carry out machining precisely and finely, it is important to set the relative cutting edge height of the tool to the work accurately. For example, in cutting a work into a tapered shape, the work might end up having an incomplete cutting end, as is often the case if the cutting edge height of the tool is not adapted to the work. If such an incomplete cutting end occurs, the position of the tool is adjusted and cutting is again applied so that the incomplete cutting end disappears. This is disadvantageous in terms of the number of machining steps required, etc.
As a technique conscious of cutting edge height adjustment, for example, the technique disclosed in Unexamined Japanese Patent Application KOKAI Publication No. 2000-33502 can be raised.
The device disclosed in the above-indicated patent literature has a positioning means which determines the relative vertical positions of a tool and a main spindle unit for holding and rotating a work.
The device of the above-indicated patent literature can set a ball screw, a slide, a motor, an NC unit, an encoder, a linear scale, etc. in place. Hence, this device can efficiently adjust the cutting edge height of a tool to match a work.
However, this device might get the cutting edge to deviate from the height set relative to the work, during machining the work. Nevertheless, this device is not taken any care of, about deviations that might arise correspondingly to the condition of machining.